Shirou and Rider
Shirou looked at Vanguard with confusion. How could he be "Sakura's protector". That was Rider's job.
"But, Rider is Sakura's protector...", he said with confusion.
"And, yes, I have met the other Shirou. He is this Sakura's true love, I have upset her greatly. I have my own beloved Sakura, though, who is out there somewhere in this city. I need to find her", he continued.
Then, suddenly, they heard a loud scream.
"Shut up! Please—!" Sakura shouted.
Shirou looked in the direction, desperately wanting to go and help her, but he held himself in check. She had no wish to see him, or to be anywhere near him, and he would respect that wish.
Rider, however, knew she had to help her master. She ran towards the room. She arrived just after Shirou had kicked the door open to reveal Sakura's shadow, seemingly "attacking" Rin.
"What did you do?" Shirou said with a scowl, holding on to Sakura as he did.
"Nothing, we were just talking and she had some fit", Rin replied.
Rider tensed up. She could see that Rin was still in combat mode and, whilst it was unlikely that Rin truly and genuinely loved Sakura, Rider knew that her dedication to Sakura's well-being was not quite as absolute as hers or, even, Shirou's.
Rider approached Sakura carefully, trying to both protect Rin and, if necessary, protect Sakura from Rin.
"Sakura, are you OK?" she said with great concern.